Electronic device for transposing signals



Feb. 4, 1958 w. E. w; JACOB 2,822,469

ELECTRONIC DEVICE TRANSPOSING SIGNALS Filed 001?. l, 1954 nited States Patent ELECTRONIC DEVICE FOR TRANSPOSING SIGNALS Walter Emil Wilhelm'Jacob, Hagersten, Sweden, assignor to Telefonaktiebolaget LMEri'csson, Stockholm, Sweden,-a corporation ofSweden Application October 1, 1954, Serial No. 45,719 Claims priority, application Sweden November 11, 1953 Claims. (Cl. 250-27) The present invention relates to a device for transposing of signals, for'example impulses, in such a manner, that an impulse fed to the input of the device is received at its output as an impulse having the same sign or the opposite sig'n, oris entirely suppressed, so that no signal arises.

The device according to the invention comprises electron tubes with at least one electron emitting cathode, means for acceleration and control of theelectron current emitted from the cathode, a number of dynodes operating within a certain range, and one or more collector electrodesfor collecting the primary electron current and the secondary electron currents, all the dynodesof said tubes being individually electrically available directly from outside. The dynodes are connected over suitably dimensioned resistances to positive sources of potential, the potential of which. is greater than, smaller than or equal to the potential of the collector electrodes, depend ing upon whether the signal applied to the input of the tube is to have, at the output of the respective dynode circuit, the opposite sign or the same sign, or whether it is not to appear at all.

The invention will be described more in detail in connection with the'accompanying drawings, in which:

Fig. 1 shows a tube of the kind to which the invention may be applied,

Fig. 2 shows the current voltage characteristics of a dynode in a tube according to Fig. 1,

Fig. 3 shows a connecting device according to the invention.

The tube according to Fig. 1 comprises a filament cathode k, a control grid. g usually operating with negative potential, a positive acceleration grid 32, a collector electrodeg and a number of dynodes 2. An electron current emitted at the cathode. During both control and acceleration, flows partly directly to the collector electrode and partly to the dynodes e. As long as these dynodes operate at cathode potential the electrons will not reach them, but if a dynode is fed with positive potential an electron current flows thereto. To begin with said current increases with increasing potential, but owing to a starting secondary emission it does not increase linearly with the voltage but passes a maximum and thereafter decreases again. At a certain determined voltage, where the resulting secondary emission factor of the dynode is 1, the current becomes zero again and thereafter has negative values with increasing voltage. At a certain value of the voltage the current thus passes a minimum and thereafter rises again towards zero, which it passes at a voltage corresponding to the collector potential, thereafter becoming positive again and reaching a positive saturation value.

Fig. 2 shows three characteristics for such a dynode with the primary current 1;; of the tube as parameter, whfereby I I I These characteristics intersect each other at three points, that is, at the common zero point S and at two further points S and S where the resulting secondary emission factor is l, i. e. the dynode 2,822,469 Patented Feb. 4,

2 current is zero. The highest of said-last mentioned two points of intersection (S has practically the same voltage as the collector voltage and divides the characteristic into two ranges, a low range, where between the points S and S the secondary emission is prevailing and the dynode may thus, with regard to its operation, be considered as a cathode, and a high range, where the primary current is prevailing and the dynode may, with regard to its operation, be'considered as an anode. If for example different operating voltages V for example V V V V or V,,=V,, V then being the collector voltage, are applied to the'dynodes over suitably dimensioned' external load resistances R,,, the resistance lines R with their respective zero passages shown in Fig. 2, are obtained. The points of intersection of such lines of resistance with the dynode characteristics then show the current voltage values which appear on the dynode. In the low range V V an increase of the tube current, i. e. an increase of the voltage on thegrid g, (or g causes an increase of voltage on the dynode,.-the input and output signals thus having the same sign. In the high range, an increase of the tube current causes a decrease of voltage on the dynode, which resultsin dilferent signs for the input and output signals. At the limit point itself, S between said two ranges, a change of the tube current has however no effect on the dynode voltage, the input signal consequently being suppressed;- It is obvious that such a suppression also takes place when the dynode voltage is equal to the voltage at the other two points of intersection, i. e. when V -'V, and V,,=O. It is however not practical to use the range between and S in the present case, due to the shallowness of the characteristic.

Fig. 3 shows a circuit system'from which the principle of the invention will be more readily apparent. The input signal is here shaped as a pulse and is fed to the control grid of the tube. The grid may have such a voltage, that current flows into the tube only during the pulse time. The acceleration and collector grids are fed with contact voltage. The output'voltage is capacitively taken from the dynode circuits over the resistances R which, in a parallel connection with the resistances R form the external resistances R The voltage V the value of which determines the sign and amplitude of the output case the pulse fed to the grid supplies the time information for the storing, the voltages V V or V V being the binary numbers which, as a positive or a negative sign, are to be stored.

The invention is naturally not limited to the above disclosed embodiment but several modifications of detail may be effected within the scope of the invention.

I claim:

1. An electronic device for transposing signals, comprising an electron tube including a thermionic cathode, an acceleration electrode for accelerating the electron current emitted by the cathode, a control electrode for controlling the electron current emitted by the cathode, the signals to be transposed being fed to said control electrode, several secondary electrons emitting electrodes, a common collector electrode for collecting the primary and secondary electron currents, each of said secondary electrodes emitting electrodes being separately and directly accessible from the outside of the tube, and control circuits individual to each secondary electron emitting electrode, each including individually variable bias potential means and resistance means connected to each of said secondary electron emitting electrodes, the value of said bias potential means in relation to the operational potential of the cathode controlling the amplitude of the output signals of said secondary electron emitting elements.

2. An electronic device for transposing signals, cognprising an electron tube including a thermionic cathode, an acceleration electrode for accelerating the electron current emitted by the cathode, a control electrode for controlling the electron current emitted by the cathode, the signals to be transposed being fed to said control electrode, several secondary electrons emitting electrodes, a common collector electrode for collecting the primary and secondary electron currents, each of said secondary electrodes emitting electrodes being separately and directly accessible from the outside of the tube, and control circuits individual to each secondary electron emitting electrode, each including individually variable bias potential means and resistance means connected to each of said secondary electron emitting electrodes, the value of at least some of the bias potentials in relation to the operational potential of the cathode being greater than the operational potential of the collector electrode, whereby the output signals of the ones of the secondary electron emitting electrodes, whose bias potential is greater than the operational potential of the collector electrode have a polarity opposite to that of the input signals.

3. An electronic device for transposing signals, comprising an electron tube including a thermionic cathode, an acceleration electrode for accelerating the electron current emitted by the cathode, a control electrode for controlling the electron current emitted by the cathode, the signals to be transposed being fed to said control electrode, several secondary electrons emitting electrodes, a common collector electrode for collecting the primary and secondary electron currents, each of said secondary electrodes emitting electrodes being separately and directly accessible from the outside of the tube, and control circuits individual to each secondary electron emitting electrode, each including individually variable bias potential means and resistance means connected to each of said secondary electron emitting electrodes, the value of at least some of the bias potentials in relation to the operational potential of the cathode being smaller than the operational potential of the collector electrode, whereby the ouput signals of the ones of the secondary electron emitting electrodes, whose bias potential is smaller than the operational potential of the collector electrode, have a polarity equal to that of the input signals.

4. An electronic device for transposing signals, comprising an electron tube including a thermionic cathode, an acceleration electrode for accelerating the electron current emitted by the cathode, a control electrode for controlling the electron current emitted by the cathode, the signals to be transposed being fed to said control electrode, several secondary electrons emitting electrodes, a common collector electrode for collecting the primary and secondary electron currents, each of said secondary electrodes emitting electrodes being separately and directly accessible from the outside of the tube, and control circuits individual to each secondary electron emitting electrode, each including individually variable bias potential means and resistance means connected to each of said secondary electron emitting electrodes, the value of at least some of the bias potentials in relation to the operational potential of the cathode being equal to the operational potential of the collector electrode, whereby the output signals of the ones of the secondary electron emitting elements, whose bias potential is equal to the operational potential of the collector electrode, disappear.

5. A device according to claim 1, wherein said secondary electrons emitting electrodes are dynodes.

References Cited in the file of this patent UNITED STATES PATENTS 2,427,533 Overbeck Sept. 16, 1947 

